A young girl weeps during the funeral of a fighter with the al-Quds Brigade in Deir al-Balah, Gaza, on Sunday, Nov. 18, 2012. Israeli Prime Minister Benjamin Netanyahu warned of a ?significant? expansion of Israel?s continuing assault on Gaza, and President Barack Obama defended Israel?s right to protect itself. (Tyler Hicks/The New York Times)

A young girl weeps during the funeral of a fighter with the al-Quds Brigade in Deir al-Balah, Gaza, on Sunday, Nov. 18, 2012. Israeli Prime Minister Benjamin Netanyahu warned of a ?significant? expansion of

GAZA CITY, Gaza Strip — An Israeli bomb pummeled a home deep into the ground here Sunday afternoon, killing 11 people, including nine in three generations of a single family, in the deadliest single strike since the cross-border conflict between Israel and the militant faction Hamas escalated on Wednesday.

The airstrike, along with several others that killed civilians across this coastal territory and hit two media offices here — one of them used by Western TV networks — further indicated Israel was striking a wider range of targets. Gaza health officials reported that the number of people injured here had nearly doubled to 600 by day's end; the Palestinian death toll climbed to 70, including 20 children. Three Israelis have been killed and at least 79 wounded by continued rocket fire into southern Israel and as far north as Tel Aviv, as Israeli cities were paralyzed by an onslaught of relentless rocket fire out of Gaza for the fifth straight day.

Even as President Barack Obama, beginning an Asia visit, supported Israel's "right to defend itself," he also said that "if that can be accomplished without a ramping up of military activity in Gaza, that's preferable." And he described an urgent international effort to secure a cease-fire, saying, "We're going to have to see what kind of progress we can make in the next 24, 36, 48 hours."

But as cease-fire talks began Sunday in Cairo, both sides were digging in, officials close to the negotiations said. An emboldened Hamas made sweeping demands, including the permanent opening of the border crossing between Gaza and Egypt and the end of the Israeli blockade.

Prime Minister Benjamin Netanyahu has stuck to his demand that all rocket fire cease before the Israeli campaign lets up, and tanks and troops remained lined up outside Gaza on Sunday. Tens of thousands of reserve troops had been called up. "The army is prepared to significantly expand the operation," Netanyahu said.

In the Israeli strike Sunday morning, it took emergency workers and a Caterpillar digger more than an hour to reveal the extent of the devastation under the two-story home of Jamal Dalu, a shop owner. Dalu was at a neighbor's when the blast wiped out nearly his entire family: His sister, wife, two daughters, daughter-in-law and four grandchildren ages 2 to 6 all perished under the rubble, along with two neighbors, an 18-year-old and his grandmother.

The smell of bomb residue and the roars of bulldozers filled the air as people clambered over rubble to get a closer look. When two tiny bodies were finally found, rescuers and residents erupted in cries of "God is great!" One worker rushed the girl to an ambulance, while a neighbor grabbed the boy and just ran.

Ismail Haniyeh, the prime minister of the militant Hamas faction that rules Gaza, condemned the attack as a "massacre" that "exceeded all expectations." Brig. Gen. Yoav Mordechai, chief spokesman for the Israeli military, said it was "examining the event."

"The wanted target in this case was responsible for firing dozens of rockets into Israel," he added. "I do not know what happened to him, but I do know that we are committed to the safety of the citizens of Israel."

Israelis awoke Sunday to a new blitz of Palestinian rockets that totaled nearly 100 by nightfall, including two that soared toward the population center of Tel Aviv but were knocked out of the sky by the Iron Dome missile defense system.

One rocket crashed through the roof of an apartment building in Ashkelon, a few miles up the coast from Gaza, where residents escaped serious injury because they had heeded the warning siren and run to lower floors. Four people were injured, two of them seriously, when a rocket exploded near their car in Ofakim, and a firefighter in Nachal Oz was seriously hurt by shrapnel.

A barrage of 10 missiles rained on Ashdod; nine were intercepted and the 10th hit an eight-story building but did not explode, heightening fears as residents were told to remain inside.

Routine activity in the region ground to a halt as people huddled in bomb shelters, where many have even been spending the night. Few people walked in the street. "I am the kind of person that always checks where the bathrooms and the exits are," said Carol Erdheim, who lives in Ashdod. "Now you look for where the safe room is. You just know what to do. It is a way of living."

There are no warning sirens here in the Gaza Strip, where the wee hours of Sunday were punctuated by airstrikes as well as a series of missiles fired from Israeli Navy vessels off the coast. Later in the morning, Mutassim Essifan, 5, and his 1-year-old sister, Jumana, were killed in the Jabiliya Refugee Camp near the northern border, followed by another baby in the Al Buraj Refugee Camp midstrip and, by lunchtime, a 52-year-old woman in the eastern part of Gaza City. Ahmed Al-Nahal, 24, a member of Hamas' military wing, and his relative Tasnim, 8, were killed before lunchtime in the Beach Refugee Camp, where Haniyeh lives.

Among the buildings Israel hit overnight were two containing the offices of local media outlets, in what the military described as an attempt to derail Hamas communications. The Israeli Air Force also briefly took control of Hamas' radio network Sunday, broadcasting a message to Gaza residents. "Hamas is playing with fire and risking you," it warned. "We recommend that you stay away from the places of terrorists and the infrastructure of Hamas."

Ayman Amar, a spokesman for al-Quds television, said seven camera operators and editors were resting on couches in their 11th-floor offices in the Shawa and Hossari building in downtown Gaza City around when a missile from an Israeli helicopter ripped through the roof at 1:30 a.m. All seven were injured, one losing a leg below the knee, Amar said, but they escaped before three more bombs dropped 10 minutes later.

"This will not deter us from showing the truth to the world," he said. "We will not stop. It is our duty toward our cause to support the Palestinian people."

Salama Marouf of the Hamas media office called the attack "an immoral massacre against the media," and the Jerusalem chapter of the Foreign Press Association lodged a protest; several international outlets, including Fox News, Sky News, CBS and Germany's ARD television, used productions studios in the two targeted media buildings.

Israel's Vice Prime Minister Moshe Ya'alon, who is in charge of strategic affairs, told reporters that the strike "didn't intend to target journalists," and said he had asked the military to investigate. "The attack helicopters were to hit Hamas military antenna — that was the target, not journalists."